基于短路阻抗及ΔU-I_(1)轨迹特征联合分析的变压器绕组变形故障在线检测方法

Online detection method of transformer winding deformation based on combined analysis of short circuit impedance andΔUI_(1) locus characteristics

为解决短路阻抗法不能进行故障类型识别及其与ΔU-I_(1)轨迹法均易受设备测量误差干扰的问题,提出了基于短路电抗及ΔU-I_(1)轨迹特征联合分析的绕组变形在线检测方法。介绍了在线短路阻抗法的原理,并根据互感器测量误差的短时不变性提出了减小测量误差的计算方法。介绍了ΔU-I_(1)轨迹法的原理,然后给出基于短路阻抗及ΔU-I_(1)轨迹特征联合分析的变压器绕组变形在线检测步骤和判据。通过建立变压器的仿真模型,对所提方法的有效性及考虑测量误差时的准确性进行了验证。结果表明,所提方法能在考虑测量误差时准确识别变压器的绕组变形故障,具有工频带电监测和故障类型识别的优点,提高了绕组变形故障识别的精度。

In order to solve the problem that the short circuit impedance method cannot identify fault types and that both the short circuit impedance method and theΔUI_(1)locus method are susceptible to the interference of equipment measurement errors,an online winding deformation detection method based on the combined analysis of short circuit impedance andΔUI_(1)locus characteristics is proposed.The principle of online short circuit impedance method is introduced,and a calculation method of short circuit impedance based on the short time invariance of measurement error is put forward to reduce the measurement error.The principle ofΔUI_(1)locus method is introduced,then the online detection steps and criteria of transformer winding deformation based on combined analysis of short circuit impedance andΔUI_(1)locus characteristics are given.The effectiveness of the proposed method and its accuracy considering measuring errors are verified by establishing a transformer simulation model.The results show that the proposed method can accurately identify transformer winding deformation faults when considering measurement error,and has the advantages of live detection and fault type identification,which improves the identification accuracy of winding deformation fault.